Grinding machine having a motor driven wheel spindle



Feb. 2 7, 1934. w DUNBAR 1,948,848

GRINDING MACHINE HAVING A MOTOR DRIVEN WHEEL SPINDLE Filed may 18, 1952 F161 I'NVE is HOWARD 14 WITNESSES a 5. um @qaaw ulcerated Fells; 2? i934 Lll ldfid GMNDENG- MUM) HAVING A MGTQE IlllltlWE-N WHEEL SPKNELE Howord W. Elector, Worcester, Mass, assiguor to Norton Company, Worcester, Mess, at cor por'etiou ofi Massachusetts Application. Mary 1%, N32. Serial No. 612.0%

2 @luims.

This invention relates to grinding machines, and more particularly to a grinding wheel slide spindle hearing. and driving mechanism having on integral built-in driving motor with on air circulating system for cooling the same.

Heretofore, grinding machine spindles have been driven in different ways, such as on overheed belt drive, a belt drive from a.- drive shaft within the base of the machine, and e belt drive from a motor driving a main shaft on the wheel slide or the rear of the machine. These construc-r tions hove all involved u flexible driving connection loetween the prime mover and the driven spindle. it. flexible driving medium, such as o. belt or chain, necessitates attention on the port of the operator to mcmteirung it in proper driving condition so that the tension of the belt will insure a constant and uniform rotation of the wheel spindle. As the belt wears and ages, its driving qualities become less efiicient.

"it is the primary object of this invention to minimize these difiioulties and to provide a. builtin motor drive for e. grinding wheel spindle, in which a flexible driving medium is eliminated;

"it is a. further object of this invention to provide a, built-in motor drive for a grinding wheel spindle, in which the stator of the motor is re mo /ably supported in an enlarged portion of the wheel slide and in which the rotor surrounds and is fixedly mounted to rotate with the wheel spindie.

"it is s further object of this invention to provide a, self-contained, coolant system for circulcting air around and between the motor parts to cool the some during grinding.

Other objects will be apparent from the following disclosure. One embodiment of this inventlon has been illustrated in the accompanying drawing, in which like reference numerals indicate like parts.

Fig. l is a fragmentary cross-=sectional view, through a, grinding machine wheel slide embodymg this invention;

Fig. 2 is a fragmentary front elevation on the machine, having ports broken awsy and shown in section to moreclearly show the support for the wheel slide and its actuating mechanism;

Fig. 3 is a fragmentary cross-sectional view I taken approximately on the line 3-3 ofv Fig. 2;

and

Fig. i is a. fragmentary cross sectional-view, showing the support for the motor stator.

In accordance with this invention, a, grinding machine is provided with a. transversely movable wheel slide which rotatably supports a grinding (ill. Ell-lot) .wheel spindle in adjustable bearings secured therein. An enlarged integral portion of the wheel slide is formed with a cylindrical bore which is arranged to support an electric motor stator. The grinding wheel spindle is arranged to support a. motor mmature in proper relation with the stator. An air circulating system is provided to circulate cool air around and between the motor parts to cool the same during the grinding operation. This mechanism comprises a. fan mounted on the wheel spindle which is or ranged to draw air from outside the enlarged portion and to iorce air through and around and between the motor parts and force the warm air out through apertures at the other end or enlarged casing.

As illustrated in the drawing, a surface grind mg machine, of the type disclosed in the prior patent to Norton No. messes dated December ill, 1915, has been shown having e base to which is arranged to support at work table ii. for longi tudinal movement thereon. A transversely mow able wheel slide 12 is arranged to support e. wheel spindle 13 in 2. pair of odiustuhle sleeve hearings i l and 15 of standard construction, which ere 1 located at opposite ends of the slide 12. e. grinding wheel 16 is mounted. on the outer end or the wheel spindle 13. As illustrated in the drawing. the transversely movable wheel slide '12 is mouht ed in a, vertically movable slide 20 which is or ranged for adjustment vertically on 2, slidewey 21 by means of e. iced screw 22.

The wheel slide 12 is srranged for o, trans-- verse feeding movement which, as illustreted comprises a. rack her 25 fixedly mounted on the slide 12 and c pinion 26 which is rotctebly sup ported in the vertical slide 20 and meshes with the rack 25. The pinion 26 is mounted on one end of a. rotatable shaft 27 which is journoled in the vertical slide 20. The other end of the shaft 2*! is provided with u worm gear .28 which in turn meshes withthe worm. 29 on the shaft to.

It is frequently necessary and desiruble thet the wheel be fed rapidly during some operations sndslowly for truing the wheel or for e finishmg operation. To accomplish this result, a. hand wheel 31 is mounted on the outer end of the shaft and is arranged so that it may be turned to rotate the shaft 30 directly to advance the wheel rapidly. 1

For a; slow feeding movement, 9. hood wheel 35 is provided which is mounted on the outer end. of a shaft 36. The inner end of the sheit 36 is provided with. a. worm '3'? meshing with a worm gear 38 which is freely rotatable on o the v The wheel slide 12 is provided with an enlarged I integral casing 50 having a cylindrical bore 51 arranged to receive an electric motor stator 52 which is held in place by set screws 53. A motor rotor 55 is keyed to the tapered portion 56 of the spindle 13 and is held in place thereon by means of a locking collar 57. To permit ready accessto the motor parts, the opening end of the cylindrical bore 51 is enclosed by an end cap 58 secured by screws to the end of casing '50 and which in turn supports the adjustable radial thrust'bearing 15 and also an end thrust bearing 59. The adjustable bearing 14 is supported in an'integral part of the wheel slide 12. The electric motor stator and rotor may be of any standard well-known constructions of constant speed, multi-spee'd or variable speed types.

In an encased built-in motor construction of this type, it is desirable that the parts of themotor be adequately cooled to maintain eflicient operation oi'the machine. In the preferred construction, an air circulating system is provided, which includes a fan 60 which is fixedly mounted on 'a projecting portion 61 oi'the spindle 13 which is outside the radial bearing 15 and the end thrust bearing 59. The Ian 60 is surrounded by a perforated guard 62 which inturn is fastened to the end cap 58, It will be readily appreciated from this construction that by removing the end cap 58 together with the bearing, the parts of the motor are made readily accessible. Air is drawn in ough the perforation 63 in guard 62, passes through perforations 64 in the end cap and is directed by the tunnelshaped flange 65 to pastes 66 in the armature, passages 67 outside the stator and also in the gap between the stator d the rotor. Air then passes out through the perforations 68 adjacent the other end of the emerged integral motor The invention has been illustrated and described as applied to a surface grinding ma. chine, but the invention is equally applicable to a cylindrical grinding machine, such as that shown in the expired patent to Norton No. 762,- 838 dated June 14, 1904.

Having thus described'the invention, what is claimed as new and desired to secure by Letters Patent is: l

1. A grinding machine comprising a base, a wheel slide, a grinding wheel spindle rotatably supported on said slide, an adjustable hearing at one end of the slide to support the end of the spindle adjacent to the grinding wheel, an enlarged housing integral with the slide, a cylindrical bore therein having an open end adjacent to the other end of the spindle, a motor stator mounted within said bore, a motor armature within the stator which is fixedly mounted on thespindle to rotate the same, adjustable radial and end thrust bearings for the other end of said spindle on the opposite end oi said arma ture from the first bearing, and a removable end cap supporting said latter bearings and closing the open end of said cylindrical bore to permit access to the motor parts.

2. A grinding machine comprising a base, a wheel slide, a rotatable wheel spindle mounted on said slide, a grinding wheel on said spindle,

an adjustable bearing on the slide to support the end of the spind.e adjacent to the grinding wheel, an enlarged portion integral with said slide, a cylindrical bore therein having all open end adiacent to the other end of the spindle, a motor stator removably mounted within said bore, an armature within said stator and fixedly mounted on the spindle to rotate the same, a readily removable end cap for closing the open end of said bore, an adjustable bearing supported by said cap for rotatably supporting the other end of the wheel spindle on the opposite side 01' the armature from the first bearing, and an air circulating fan mounted outside of said second bearing to circulate air around and between the motor parts to cool the same'during HOWARD W. DUNIBAR. 

